Optically variable ink (OVI) also called color shifting ink is an anti-

counterfeiting A counterfeit is a fake or unauthorized replica of a genuine product, such as money, documents, designer items, or other valuable goods. Counterfeiting generally involves creating an imitation of a genuine item that closely resembles the original ...

measure used on many major modern

banknote A banknote or bank notealso called a bill (North American English) or simply a noteis a type of paper money that is made and distributed ("issued") by a bank of issue, payable to the bearer on demand. Banknotes were originally issued by commerc ...

s, as well as on other official documents ( professional licenses, for example). The ink displays two distinct colors depending on the angle the bill is viewed at. The

United States fifty-dollar bill The United States fifty-dollar bill (US$50) is a Denomination (currency), denomination of United States dollar, United States currency. The 18th President of the United States, U.S. president (1869-1877), Ulysses S. Grant, is featured on the obv ...

, for example, uses color shifting ink for the numeral 50 so that it displays copper at one angle and bright green in another. OVI is particularly useful as an anti-counterfeiting measure as it is not widely available, and it is used on

security printing Security printing is the field of the printing industry that deals with the printing of items such as banknotes, cheques, passports, tamper-evident labels, security tapes, product authentication, stock certificates, postage stamps, and identity c ...

. One major manufacturer is a

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

company called SICPA (Société Industrielle et Commerciale de Produits pour l'Agriculture). Additional suppliers include German company Gleitsmann Security Inks,

Sun Chemical Sun Chemical is one of the world's largest producer of printing inks and pigments and is located in Parsippany-Troy Hills, New Jersey. It was incorporated in 1945. The company has its roots as the Lorilleux & Cie. Paris in 1818, but was incorp ...

(through their Brand Protection Division based in Manchester, UK), and the Swiss company Printcolor AG, located in Berikon,

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

. Color-shifting inks reflect various wavelengths in white light differently, depending on the angle of incidence to the surface. An unaided eye will observe this effect as a change of color while the viewing angle is changed. A color copier or scanner can copy a document only at one fixed angle relative to the document's surface. It uses finely powdered pearlescent

glitter Glitter is an assortment of flat, small, reflective particles that are precision cut and come in a variety of shapes, sizes, and colors. Glitter particles resemble confetti, sparkles and sequins, but somewhat smaller. Since prehistoric times ...

or flakes of mica or an electrically insulating material such as resins or plastics with at least two metal-based, optically reflective compounds on top deposited by physical vapor deposition, that cause light interference. It is similar to paint containing

ChromaFlair ChromaFlair is a pigment used in paint systems, primarily for automobiles. When the paint is applied, it changes color depending on the light source and viewing angle. It was created at Optical Coating Laboratory, Inc. (OCLI) ater JDS Uniphase ...

pigment.

Optically variable magnetic ink

Optically variable magnetic ink (OVMI), also called SPARK, has visual effects that are based on the magnetic properties of the ink. When the document is tilted, movement of a bright light stripe occurs and the colour changes. It is usually applied by screen printing. This type of ink is used for the

Euro The euro (currency symbol, symbol: euro sign, €; ISO 4217, currency code: EUR) is the official currency of 20 of the Member state of the European Union, member states of the European Union. This group of states is officially known as the ...

Brazilian real The Brazilian real (plural, pl. '; currency symbol, sign: R$; ISO 4217, code: BRL) is the official currency of Brazil. It is subdivided into 100 centavos. The Central Bank of Brazil is the central bank and the issuing authority. The real repl ...

, and

Russian ruble The ruble or rouble (; Currency symbol, symbol: ₽; ISO 4217, ISO code: RUB) is the currency of the Russia, Russian Federation. Banknotes and coins are issued by the Central Bank of Russia, which is Russia's central bank, monetary authority ind ...

banknotes.

References

{{Reflist Money forgery